lenco reverser ?

I am assembling my reverser.
When you install the shaft with the sun gear and forward drive gear on it thru the planetary and bearing , there is a snap-ring that goes on the other side of the case where the sprag goes.
When you install that snap ring , is there suppose to be a thin shim between the bearing and snap-ring? There was a shim in mine when I took it apart and it seems like there would be quite a bit of end-play without it but... nowhere in Lencos assembly drawing does it show this shim !

 

Yes, both of my transmissions have them also.

 

thank you ! I figured that it was an optional piece, but... just thought id ask